The invention relates to a covering for an air bag which is folded and accommodated in a receiving compartment of a motor vehicle which can be closed by the covering. The airbag is automatically inflated to form an impact cushion for an occupant in the event of an accident involving the motor vehicle, the covering tearing open at given intended tearing lines. A special cladding is provided for the covering which consists of tear-resistant material, such as in particular leather, and is slotted at intended tearing lines which may be covered by it.
Very many motor vehicles are already equipped with occupant restraint systems as standard features, in which air bags which protect the driver and passenger are automatically inflated in the event of an accident. Systems of this type have proved to be expedient in practice.
When not in use, each air bag is accommodated in a folded state in a receiving compartment which can be formed on the driver's side, for example by a box arranged as the hub of the steering wheel. On the passenger side, an appropriate recess, for example in the form of a housing, is usually provided in the dashboard or instrument panel. These accommodation compartments are normally closed on the exit side of the respective air bag by a covering which is usually of cushion-like construction, is provided with intended tearing points or lines and can accordingly be torn open relatively easily by the air bag which is inflated in the event of an accident.
For reasons of tastefulness, the covering has on its side facing the occupant a cladding which can consist of leather, for example according to German Patent Document DE-A 4,035,975 and British Patent Document GB-A 2,252,274.
Since leather and similar materials are very resistant to tearing, if this material passes over intended tearing points or lines of the covering, it must be interrupted at such sites by slots.
According to German Patent Document DE-A 4,035,975, the edges of the pieces of leather next to the slots can form seams which are folded inwards, it being possible for the seamed edges of the pieces of leather to be connected to one another invisibly to the greatest extent by an easily tearable web of paper or the like which is covered to the greatest extent by the seamed edges of the pieces of leather.
Provision is made according to British Patent Document GB-A 2,252,274 for the covering to have narrow slots at the intended tearing points or lines, by means of which slots the edges of the pieces of leather are held.
Leather claddings of this type may indeed be preferred by the purchasers of the motor vehicles for reasons of tastefulness, but they have the basic disadvantage of a relatively high price since the manufacture and mounting are comparatively expensive.
It is known from German Patent Document DE-A 4,034,539 and U.S. Pat. No. 5,002,306 to integrate membrane switches in the covering of an air bag or to arrange them on the surface of the covering in order to be able to utilize the surface of this covering, which is relatively easily accessible and comparatively large, for controls of the motor vehicle. However, the arrangement of membrane switches on the covering is not exactly unproblematic because the covering is burst open in the manner of an explosion during inflation of the air bag, in which case the membrane switches can become detached from the covering and injure occupants of the vehicle.
An object of the invention is now to provide a cladding made of leather or comparable material, which is particularly attractive in terms of tastefulness, for the covering of an air bag with comparatively low expense.
According to the invention, this object is achieved in that the covering is constructed as a support of a membrane switch arrangement which, for its safety during inflation of the air bag and during the tearing open of the covering thus caused, is connected to the cladding by sewing so as to be resistant to tearing.
According to the invention, the cladding of the covering of the air bag thus has a dual function, in that, on the one hand, it serves for the tasteful design of the covering due to the corresponding material, such as for example leather, and, on the other hand, takes over the task of securing the membrane switch arrangement. In this case, the high resistance to tearing of leather and similar material is particularly advantageous. Additionally, the connection of the cladding or of the leather to the membrane switch arrangement by sewing can be carried out relatively easily during production because these are production methods which are in any case customary in the manufacture of the cladding.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.